"It has been almost a decade after the landmark moratorium on all climate-related geoengineering was passed by the Convention on Biological Diversity (CBD) in 2010 and several years since the decision of parties to the London Protocol of the London Convention on marine dumping prohibiting ocean fertilization and potentially other marine geoengineering proposals. Today, geoengineering is on the agenda of another UN body: the UN Environment Assembly." LINK

"Geoengineering technologies are not yet deployable globally, but support for them is advancing fast, thanks to backing by powerful advocates eager to start experiments. But no silver bullet for climate change exists, and we must not abandon proven methods for the sake of a promise that one will be found." LINK

Project Goal

The key goal of the project is an objective and comprehensive assessment of potential effects, side-effects, and uncertainties of different Climate Engineering (CE) methods and emission reduction measures. This will be done using simulations with Earth system models. Special focus lies on scenarios combining different CE measures, detection of signals and uncertainty assessments. Different CE methods (e.g., afforestation, radiation management, ocean alkalinity enhancement) will be simulated under various CO2 emission scenarios. Effects and side-effects will be compared by using different metrics (Fig. 1).

Fig. 1: Exemplary set of societally relevant target variables, which could enter an assessment of CE methods and emission reduction measures.

C O R E Q U E E S T I O N S

How can different CE and CO2 emission reduction scenarios be assessed comparatively by using model simulations?

What are the interactions between different CE methods in portfolio scenarios?

How can land-, ocean- and atmosphere-based CE be detected and attributed consistently?

How large are the effects of uncertainties in Earth system models and what is their role in the comparative assessment?

Methods

Fig. 2: Schematic depiction of the complex Max Planck Institute Earth System Model (MPI-ESM) and the UVic model which is envisaged as an emulator.

To simulate the large-scale deployment of different CE schemes two Earth system models will be used: the relatively simple, computationally fast University of Victoria Earth System Climate Model (UVic ESCM) and the more complex but computationally more costly Max Planck Institute Earth System Model (MPI-ESM).

"It has been almost a decade after the landmark moratorium on all climate-related geoengineering was passed by the Convention on Biological Diversity (CBD) in 2010 and several years since the decision of parties to the London Protocol of the London Convention on marine dumping prohibiting ocean fertilization and potentially other marine geoengineering proposals. Today, geoengineering is on the agenda of another UN body: the UN Environment Assembly." LINK

"Geoengineering technologies are not yet deployable globally, but support for them is advancing fast, thanks to backing by powerful advocates eager to start experiments. But no silver bullet for climate change exists, and we must not abandon proven methods for the sake of a promise that one will be found." LINK